Fix up some module docs formatting errors.

cloud/digital_ocean

@@ -53,7 +53,7 @@ options:
      - Numeric, this is the id of the image you would like the droplet created with.
   region_id:
     description:
-     - Numeric, this is the id of the region you would like your server in IE: US/Amsterdam.
+     - "Numeric, this is the id of the region you would like your server"
   ssh_key_ids:
     description:
      - Optional, comma separated list of ssh_key_ids that you would like to be added to the server

cloud/rds

@@ -23,10 +23,11 @@ description:
 options:
   command:
     description:
-      - Specifies the action to take.  Must be one of: create | replicate | delete | facts | modify
+      - Specifies the action to take.  
     required: true
     default: null
     aliases: []
+    choices: [ 'create', 'replicate', 'delete', 'facts', 'modify' ]
   instance_name:
     description:
       - Database instance identifier.
@@ -142,7 +143,7 @@ options:
     aliases: []
   maint_window:
     description:
-      - Maintenance window in format of ddd:hh24:mi-ddd:hh24:mi.  (Example: Mon:22:00-Mon:23:15) If not specified then a random maintenance window is assigned. Used only when command=create or command=modify.
+      - "Maintenance window in format of ddd:hh24:mi-ddd:hh24:mi.  (Example: Mon:22:00-Mon:23:15) If not specified then a random maintenance window is assigned. Used only when command=create or command=modify."
     required: false
     default: null
     aliases: []
@@ -154,7 +155,7 @@ options:
     aliases: []
   backup_retention:
     description:
-      - Number of days backups are retained.  Set to 0 to disable backups.  Default is 1 day.  Valid range: 0-35. Used only when command=create or command=modify.
+      - "Number of days backups are retained.  Set to 0 to disable backups.  Default is 1 day.  Valid range: 0-35. Used only when command=create or command=modify."
     required: false
     default: null
     aliases: []

system/service

@@ -58,7 +58,7 @@ options:
         required: false
         default: 'default'
         description:
-        - For OpenRC init scripts (ex: Gentoo) only.  The runlevel that this service belongs to.
+        - "For OpenRC init scripts (ex: Gentoo) only.  The runlevel that this service belongs to."
     arguments:
         description:
         - Additional arguments provided on the command line